1. Field of the Invention
The disclosure relates to a package structure, and more particularly to a wafer level package structure for temperature sensing elements.
2. Description of the Related Art
Presently, infrared (IR) video camera has been applied to record and store successive thermal images. The infrared (IR) video camera includes a temperature sensing chip, which includes an array of temperature sensing elements. Each temperature sensing element may change its resistance value correspondingly according to the energy of the received infrared radiation thereof. Thus, the resistance value change of each temperature sensing element may correspond to the strength of the thermal energy, and each array of temperature sensing elements array may then produce a thermal image.
The temperature sensing chip is disposed on a base, and the base is packaged with a cover. The package space is maintained in a vacuum state in order to prevent thermal convection produced in the package space from affecting the thermal energy which is detected by the array of temperature sensing elements. Also, the sensitivity of the array of temperature sensing elements is related to the vacuum level of the package space.
Since mobile phones are generally disposed with a camera, how to increase the application of this camera is the scope in which many manufacturers may concern. If the application of thermal sensing technology can be increased for the camera of the mobile phone, i.e. the camera of the mobile phone can also detect temperature and produce a thermal image, it would be good news to the consumers. However, the current prices of temperature sensing cameras are still so high that it is not favorable to be popularized. At the same time, the volume of the traditional temperature sensing camera is also too large and is not suitable to be installed on the mobile phone. Thus, if the manufacturing cost of temperature sensing camera can be reduced and the volume of temperature sensing camera can be decreased, it will facilitate its application on the mobile phone.